Substrate treating apparatus with inter-unit buffers

ABSTRACT

The invention provides coating units, heat-treating units, and a first main transport mechanism for transporting substrates to each of these treating units. The substrates are transferred from the first main transport mechanism to a second main transport mechanism through a receiver. When a substrate cannot be placed on the receiver, this substrate is placed on a buffer. Thus, the first main transport mechanism can continue transporting other substrates. The other substrates in the treating units are transported between the treating units without delay, to receive a series of treatments including coating treatment and heat treatment as scheduled. This prevents lowering of the quality of treatment for forming film on the substrates.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.12/324,794, filed on Nov. 26, 2008, which claims priority to JapanesePatent Application No. JP2007-310676, filed on Nov. 30, 2007, the entiredisclosure of which is hereby incorporated by reference its entirety forall purposes.

BACKGROUND OF THE INVENTION

This invention relates to a substrate treating apparatus for performinga series of treatments of substrates such as semiconductor wafers, glasssubstrates for liquid crystal displays, glass substrates for photomasks,and substrates for optical disks (hereinafter called simply“substrates”).

Conventionally, this type of substrate treating apparatus is used toform a resist film on substrates, and develop the substrates exposed ina separate exposing machine. The apparatus includes a treating sectionhaving arranged therein at least a coating block for forming film suchas resist film, a developing block for developing the substrates, and.Each treating block includes a single main transport mechanism andvarious treating units. The treating units of the coating block includecoating units for applying treating solutions to the substrates, andheat-treating units for heat-treating the substrates. The main transportmechanism of each block, while transporting substrates to the treatingunits in that block, transfers the substrates through receivers to andfrom the main transport mechanism of another adjacent treating block, tocarry out a series of treatments of the substrates (as disclosed inJapanese Unexamined Patent Publication No. 2003-324139, for example).

The conventional apparatus with such a construction has the followingdrawbacks.

In the conventional apparatus, when the main transport mechanism of thecoating block transfers a substrate to the other adjacent main transportmechanism, the substrate cannot be placed on a receiver if, for example,a different substrate is present on that receiver. In such a case, themain transport mechanism of the coating block stands by until thereceiver becomes capable of receiving the substrate. While the maintransport mechanism of the coating block is on standby, the maintransport mechanism does not transport substrates between the treatingunits of the coating block. For example, even when a substrate has beentreated in a coating unit, this substrate is not transported to anothertreating unit such as a heat-treating unit. Therefore, the coating blockcannot carry out a series of treatments including coating treatment andheat treatment in a predetermined time. As a result, there is aninconvenience of lowering the quality of treatment of the substrates.

SUMMARY OF THE INVENTION

This invention has been made having regard to the state of the art notedabove, and its object is to provide a substrate treating apparatus thatcan prevent lowering the quality of treatment for forming film onsubstrates.

The above object is fulfilled, according to one embodiment of thisinvention, by a substrate treating apparatus comprising a film formingsection for forming film on substrates, including coating units forapplying a treating solution to the substrates, and heat-treating unitsfor heat-treating the substrates; a first main transport mechanism fortransporting the substrates to and from the coating units and theheat-treating units; a receiver for receiving the substrates in order totransfer the substrates having the film formed thereon in the filmforming section from the first main transport mechanism to a differentmain transport mechanism; and a buffer disposed adjacent the receiverfor temporarily holding the substrates.

According to this embodiment, since the buffer is provided adjacent tothe receiver, even when the first main transport mechanism cannot placea substrate on the receiver, the first main transport mechanism canplace that substrate on the buffer. Thus, the first main transportmechanism can continue transporting substrates. That is, othersubstrates can be transported to the coating units and heat-treatingunits without delay. The film forming section can carry out a series oftreatments including coating treatment in the coating units and heattreatment in the heat-treating units for a plurality of substrates ontime (as scheduled). This can prevent lowering of the quality oftreatment to form film on the substrates.

In the embodiment noted above, the first main transport mechanism may bearranged to place the substrates temporarily on the buffer when thefirst main transport mechanism cannot place the substrates on thereceiver. The first main transport mechanism places the substrates onthe buffer when unable to place the substrates on the receiver, to beable to start other substrate transporting operations promptly. Thus,the treatment in progress in the film forming section can be continuedon time (as scheduled). This can prevent lowering of the quality oftreatment to form film on the substrates.

In the embodiment noted above, the different main transport mechanismmay be permitted to receive the substrates placed on the buffer. Then,the substrates can be transported efficiently since this arrangementdoes not require the first main transport mechanism to transport thesubstrates from the buffer to the receiver in order to transfer thesubstrates placed on the buffer to the different main transportmechanism.

In the embodiment noted above, the different main transport mechanismmay be permitted to place the substrates on the receiver in order totransfer the substrates to the first main transport mechanism, and alsopermitted to place the substrates temporarily on the buffer. Then, thesubstrates can also be transferred from the different main transportmechanism to the first main transport mechanism through the receiver,and in addition the different main transport mechanism also can placethe substrates temporarily on the buffer. No delay will occur in thesubstrate transport by the different main transport mechanism even whenthe different main transport mechanism cannot place the substrates onthe receiver for transferring the substrates from the different maintransport mechanism to the first main transport mechanism. Thus, thereis no possibility of adversely affecting the quality of substratetreatment.

The different transport mechanism may be arranged to place thesubstrates temporarily on the buffer when the different main transportmechanism cannot place the substrates on the receiver. Since thedifferent main transport mechanism places the substrates on the bufferwhen unable to place the substrates on the receiver, there will occur nodelay in the substrate transport by the different main transportmechanism.

The buffer may be stacked with the receiver. Then, the first maintransport mechanism can selectively access both the receiver and bufferonly by moving vertically.

In the embodiment noted above, the buffer may be disposed in at leastone of positions over and under the receiver. Then, the first maintransport mechanism can selectively access both the receiver and bufferonly by moving up and down.

In the embodiment noted above, the buffer may be arranged to accommodatethe substrates corresponding in number at least to the number ofsubstrates that can be treated simultaneously in the film formingsection. Then, all the substrates that can be treated simultaneously inthe film forming section can be placed temporarily on the buffer.Therefore, at whatever time it may become impossible to place thesubstrates on the receiver, the first main transport mechanism cansmoothly transport all the substrates being treated in the film formingsection at that time. The series of treatments in the film formingsection can be completed for each substrate as usual. Thus, even when itbecomes impossible to place the substrates on the receiver while thefilm forming section is treating the substrates, there is no possibilityof lowering the quality of ongoing treatment of the substrates.

The buffer may be arranged to accommodate the substrates correspondingin number at least to the number of coating units. Even when the firstmain transport mechanism becomes unable to place the substrates on thereceiver while the substrates are being treated in the coating units,the first main transport mechanism can transport, at predeterminedtimes, all the substrates being treated in the coating units. Thus, evenwhen it becomes impossible to place the substrates on the receiver whilethe coating units are treating the substrates, there is no possibilityof lowering the quality of ongoing treatment of the substrates.

In the embodiment noted above, the film forming section may be arrangedto form resist film on the substrates. Then, resist film can be formedon the substrates with high quality.

The film forming section is arranged to form also anti-reflection filmon the substrates. Then, anti-reflection film can be formed on thesubstrates with high quality.

In another aspect of the embodiment, a substrate treating apparatuscomprises a film forming section for forming film on substrates,including coating units for applying a treating solution to thesubstrates and heat-treating units for heat-treating the substrates; afirst main transport mechanism for transporting the substrates to andfrom the coating units and the heat-treating units; a receiver forreceiving the substrates in order to transfer the substrates from thefirst main transport mechanism to a different main transport mechanism;a buffer disposed adjacent the receiver for temporarily holding thesubstrates; and a controller for controlling the first main transportmechanism to place on the receiver the substrates to be transferred tothe other main transport mechanism, and to place the substratestemporarily on the buffer at an abnormal time when the substrates cannotbe placed on the receiver.

According to this embodiment, the first main transport mechanismtransports the substrates to and from the coating units and theheat-treating units. The coating units apply a treating solution to thesubstrates, and the heat-treating units heat-treat the substrates. As aresult, film is formed on the substrates. When the substrates can beplaced on the receiver, the first main transport mechanism places thesubstrates with film formed thereon on the receiver to transfer thesubstrates to the different main transport mechanism. At an abnormaltime when the substrates cannot be placed on the receiver, the firstmain transport mechanism places the substrates temporarily on thebuffer. The controller controls the substrate transport of the firstmain transport mechanism to the receiver and the buffer. Therefore,whether an abnormal time or not, there occurs no delay in the substratetransport by the first main transport mechanism. The treatments in thecoating units and heat-treating units can be carried out for thesubstrates on time (as scheduled). This can prevent lowering of thequality of treatment to form film on the substrates.

In the embodiment noted above, the apparatus may further comprise afirst detector for detecting the substrates placed on the receiver;wherein the controller is arranged to cause the substrates to be placedtemporarily on the buffer when, in transferring the substrates from thefirst main transport mechanism to the different main transportmechanism, the controller determines from a result of detection by thefirst detector that one of the substrates is present on the receiver.With the first detector provided, the controller can reliably determinewhether or not this is an abnormal time when the substrates cannot beplaced on the receiver.

In the embodiment noted above, the controller may be arranged, whencausing the first main transport mechanism to place the substratestemporarily on the buffer, to cause the different main transportmechanism to receive the substrates placed on the buffer. Then, thesubstrates can be transported efficiently since this arrangement doesnot require the first main transport mechanism to transport thesubstrates from the buffer to the receiver in order to transfer thesubstrates placed on the buffer to the different main transportmechanism.

In a further aspect of the embodiment, a substrate treating apparatuscomprises a resist film coating block including resist film coatingunits for applying a resist film material to substrates andheat-treating units for heat-treating the substrates; a first maintransport mechanism transporting the substrates to and from the resistfilm coating units and the heat-treating units; a developing blockdisposed adjacent the resist film coating blocks, the developing blockincluding developing units for supplying a developer to the substratesand heat-treating units for heat-treating the substrates; a second maintransport mechanism for transporting the substrates to and from thedeveloping units and the heat-treating units; and an interface sectiondisposed adjacent the developing block, and including an interfacetransport mechanism for transporting the substrates to and from anexposing machine provided separately from the apparatus; wherein thefirst main transport mechanism and the second main transport mechanismtransfer the substrates through a first receiver arranged to receive thesubstrates, and the first main transport mechanism is arranged, whenunable to place the substrates on the first receiver, to place thesubstrates temporarily on a first buffer.

According to this embodiment, in the resist film coating block, thefirst main transport mechanism transports the substrates to and from theresist film coating units and the heat-treating units, and each treatingunit carries out a predetermined treatment of the substrates. As aresult, resist film is formed on the substrates. The first maintransport mechanism transfers the substrates with resist film formedthereon to the second main transport mechanism of the developing block.The substrates transported to the developing block are furthertransported through the interface section to the exposing machine to beexposed therein. The exposed substrates are transported through theinterface section to the developing block. In the developing block, thesecond main transport mechanism transports the substrates to thedeveloping units and heat-treating units, and each treating unit carriesout a predetermined treatment for the substrates. As a result, thesubstrates are developed. The second main transport mechanism transfersthe developed substrates to the first main transport mechanism.

The first main transport mechanism and second main transport mechanismtransfer the substrates between the transport mechanisms through thefirst receiver. When a substrate cannot be placed on the first receiver,the first main transport mechanism places the substrate temporarily onthe first buffer. Thus, the first main transport mechanism can transportother substrates to and from the resist film coating units and theheat-treating units without delay. The treatments in the resist filmcoating units and heat-treating units can be carried out for thesubstrates on time (as scheduled). This can prevent lowering of thequality of treatment in the resist film coating block.

In the embodiment noted above, the first buffer may be disposed adjacentand above or below the first receiver. Then, the first main transportmechanism can selectively access both the receiver and buffer only bymoving vertically.

In the embodiment noted above, each of the resist film coating block andthe developing block may be divided into stories arranged vertically.The resist film coating units, the first main transport mechanism, andthe heat-treating units of the resist film coating block may be arrangedon each story of the resist film coating block; the developing units,the second main transport mechanism and the heat-treating units of thedeveloping block may be arranged on each story of the developing block;the first receiver may be provided for each story between the resistfilm coating block and the developing block; and the first buffer may beprovided for each first receiver. A series of treatments is carried outfor the substrates in parallel on each story of the resist film coatingblock, and a series of treatments is carried out for the substrates inparallel on each story of the developing block. This can increasethroughput of the substrate treating apparatus. The stories are arrangedone over the other to form a layered structure with pluralities of firstand second main transport mechanisms and various treating units arrangedvertically, which can avoid an enlarged installation area of thesubstrate treating apparatus.

In the embodiment noted above, the interface transport mechanism may bearranged to transport the substrates to the heat-treating units of thedeveloping block where the heat-treating units carry out post-exposurebaking (PEB) treatment of the substrates exposed; the interfacetransport mechanism and the second main transport mechanism may transferthe substrates through a second receiver for receiving the substrates;and the interface transport mechanism may be arranged, when unable toplace the substrates on the second receiver, to place the substratestemporarily on a second buffer. The interface transport mechanismreceives the substrates from the exposing machine and transports thesubstrates to the heat-treating units of the developing block. Theheat-treating units of the developing block carry out post-exposurebaking (PEB) treatment for the substrates. After the post-exposurebaking (PEB) treatment, the interface transport mechanism transports thesubstrates from the heat-treating units of the developing block to thedeveloping block.

The interface transport mechanism and the second main transportmechanism of the developing block transfer the substrates between thetransport mechanisms through the second receiver. When a substratecannot be placed on the second receiver, the interface transportmechanism places the substrate temporarily on the second buffer. Thus,the interface transport mechanism can promptly start transporting othersubstrates. Specifically, the interface transport mechanism can unloadthe substrates having undergone the post-exposure baking (PEB) treatmentfrom the heat-treating units of the developing block on time (asscheduled). This can prevent lowering of the quality of post-exposurebaking (PEB) treatment given to the substrates.

In the embodiment noted above, the second buffer may be provided in theinterface section. Then, the interface transport mechanism can accessthe second buffer easily.

In the embodiment noted above, the resist film coating block may furtherinclude anti-reflection film coating units for applying a treatingsolution for anti-reflection film to the substrates. Then,anti-reflection film can be formed on the substrates with high quality.

This specification discloses embodiments directed to the followingsubstrate treating apparatus:

(1) The substrate treating apparatus according to one embodiment,wherein the buffer is arranged to receive the substrates to betransferred from the first main transport mechanism to the differentmain transport mechanism.

According to the apparatus defined in (1) above, the first maintransport mechanism can place on the buffer the substrates with filmformed thereon in the film forming section.

(2) The substrate treating apparatus according to one embodiment,wherein the buffer is arranged to receive the substrates placed by thefirst main transport mechanism.

According to the embodiment defined in (2) above, the first maintransport mechanism can place on the buffer the substrates with filmformed thereon in the film forming section.

(3) The substrate treating apparatus according to one embodiment,wherein the buffer is disposed between the first main transportmechanism and the different main transport mechanism.

According to the embodiment defined in (3) above, the first maintransport mechanism and the different main transport mechanism cantransfer the substrates conveniently.

(4) The substrate treating apparatus according to one embodiment,wherein the buffer is juxtaposed with the receiver.

According to the embodiment defined in (4) above, the first maintransport mechanism can easily access both the receiver and the buffer.

(5) The substrate treating apparatus according to one embodiment,wherein the coating units include resist film coating units for applyinga resist film material.

According to the embodiment defined in (5) above, resist film can beformed on the substrates with high quality.

(6) An embodiment of a substrate treating apparatus according to (5)above, wherein the coating units include anti-reflection film coatingunits for applying a treating solution for anti-reflection film.

According to the embodiment defined in (6) above, anti-reflection filmcan be formed on the substrates with high quality.

(7) The substrate treating apparatus according to one embodiment,further comprising a second detector for detecting the substrates placedon the buffer; wherein the controller is arranged to determine from aresult of detection by the second detector that one of the substrates ispresent on the buffer.

According to the embodiment defined in (7) above, with the seconddetector provided, the controller can reliably determine whether or nota substrate is present on the buffer.

(8) The substrate treating apparatus according to one embodiment,further comprising an anti-reflection film coating block disposedadjacent the resist film coating block, and including anti-reflectionfilm coating units for applying a treating solution for anti-reflectionfilm to the substrates, heat-treating units for heat-treating thesubstrates, and a third main transport mechanism for transporting thesubstrates to and from the anti-reflection film coating units and theheat-treating units; wherein the third main transport mechanism and thefirst main transport mechanism transfer the substrates through a thirdreceiver arranged to receive the substrates, and the third maintransport mechanism is arranged, when unable to place the substrates onthe third receiver, to place the substrates temporarily on a thirdbuffer.

According to the embodiment defined in (8) above, in the anti-reflectionfilm coating block the third main transport mechanism transports thesubstrates to and from the anti-reflection film coating units and theheat-treating units, and each treating unit carries out a predeterminedtreatment of the substrates. As a result, anti-reflection film is formedon the substrates. The third main transport mechanism transfers thesubstrates with anti-reflection film formed thereon to the first maintransport mechanism of the resist film coating block.

The third main transport mechanism and first main transport mechanismtransfer the substrates between the transport mechanisms through thethird receiver. When a substrate cannot be placed on the third receiver,the third main transport mechanism places the substrate temporarily onthe third buffer. Thus, a series of treatments in the anti-reflectionfilm coating block including coating treatment and heat treatment can becarried out for the substrates on time. This can prevent lowering of thequality of treatment for forming anti-reflection film on the substrates.

(9) An embodiment of the substrate treating apparatus according to (8)above, wherein the third buffer is disposed adjacent and above or belowthe third receiver.

According to the embodiment defined in (9) above, the third maintransport mechanism can selectively access both the receiver and bufferonly by moving vertically.

(10) An embodiment of a substrate treating apparatus comprising resistfilm coating units for applying a resist film material to substrates,heat-treating units for heat-treating the substrates, a first maintransport mechanism for transporting the substrates to and from theresist film coating units and the heat-treating units, a developingsection for developing the substrates, a second main transport mechanismfor transporting the substrates to and from the developing section, andtransferring the substrates to and from the first main transportmechanism; and a buffer for temporarily holding the substrates, thebuffer being disposed adjacent a receiver used for transferring thesubstrates from the first main transport mechanism to the second maintransport mechanism.

According to the embodiment defined in (10) above, since the buffer isprovided adjacent to the receiver, even when the first main transportmechanism cannot place a substrate on the receiver, the first maintransport mechanism can place that substrate on the buffer. Thus, thefirst main transport mechanism can continue transporting substrates.That is, other substrates can be transported to the coating units andheat-treating units without delay. A series of treatments in thesecoating units and heat-treating units is carried out for the substrateson time. This can prevent lowering of the quality of treatment to formfilm on the substrates.

(11) An embodiment of the substrate treating apparatus according to (10)above, wherein the first main transport mechanism is arranged to placethe substrates temporarily on the buffer at an abnormal time when thefirst main transport mechanism cannot place the substrates on thereceiver.

According to the embodiment defined in (11) above, even at an abnormaltime, the treatments in the coating units and heat-treating units can becarried out for the substrates on time (as scheduled).

(12) The substrate treating embodiment according to (10) or (11) above,wherein the buffer is arranged to hold a substrate to be accessible tothe second main transport mechanism, the second main transport mechanismbeing permitted to receive the substrate placed on the buffer.

According to the embodiment defined in (12) above, high transportingefficiency is assured since this arrangement does not require the firstmain transport mechanism to transport the substrates from the buffer tothe receiver in order to transfer the substrates placed on the buffer tothe second main transport mechanism.

(13) The substrate treating embodiment according to any one of (10) to(12) above, wherein the second main transport mechanism is permitted toplace the substrates on the receiver in order to transfer the substratesto the first main transport mechanism, and also permitted to place thesubstrates temporarily on the buffer.

According to the embodiment defined in (13) above, the substrates canalso be transferred from the second main transport mechanism to thefirst main transport mechanism through the receiver, and in addition thesecond main transport mechanism also can place the substratestemporarily on the buffer. Even when the second main transport mechanismcannot place a substrate on the receiver, the second main transportmechanism can start transferring other substrates promptly by placingthe above substrate on the buffer. Thus, there is no possibility oflowering the quality of treatment of the substrates in the developingsection.

(14) The substrate treating embodiment according to (13) above, whereinthe second transport mechanism is arranged to place the substratestemporarily on the buffer at an abnormal time when the second maintransport mechanism cannot place the substrates on the receiver.

According to the embodiment defined in (14) above, the second transportmechanism places a substrate temporarily on the buffer when the secondmain transport mechanism cannot place the substrate on the receiver.Thus, the second transport mechanism can transfer other substrateswithout delay.

(15) The substrate treating embodiment according to any one of (10) to(14) above, wherein the buffer is arranged to accommodate the substratescorresponding in number at least to the number of coating units.

According to the embodiment defined in (15) above, at whatever time itmay become impossible to place the substrates on the receiver, all thesubstrates being treated in the coating units at that time can receive aseries of treatments on time.

(16) The substrate treating embodiment according to (15) above, whereinthe buffer is arranged to accommodate the substrates corresponding innumber at least to a total of the number of coating units and the numberof substrates that can be treated simultaneously in the developingsection.

According to the embodiment defined in (16) above, at whatever time itmay become impossible to place the substrates on the receiver, all thesubstrates being treated in the developing section at that time canreceive a series of treatments on time.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of illustrating the invention, there are shown in thedrawings several forms, it being understood, however, that the inventionis not limited to the precise arrangement and instrumentalities shown.

FIG. 1 is a plan view showing an outline of the substrate treatingapparatus according to this invention;

FIG. 2 is a schematic side view showing an arrangement of treating unitsincluded in the substrate treating apparatus;

FIG. 3 is a schematic side view showing an arrangement of treating unitsincluded in the substrate treating apparatus;

FIG. 4 is a view in vertical section taken on line a-a of FIG. 1;

FIG. 5 is a view in vertical section taken on line b-b of FIG. 1;

FIG. 6 is a view in vertical section taken on line c-c of FIG. 1;

FIG. 7 is a view in vertical section taken on line d-d of FIG. 1;

FIG. 8A is a plan view of coating units;

FIG. 8B is a sectional view of a coating unit;

FIG. 9 is a perspective view of a main transport mechanism;

FIG. 10 is a control block diagram of the substrate treating apparatusaccording to the invention;

FIG. 11 is a flow chart of a series of treatments of substrates;

FIG. 12 is a view schematically showing operations repeated by eachtransport mechanism; and

FIG. 13 is a plan view showing an outline of a modified substratetreating apparatus.

DETAILED DESCRIPTION OF THE INVENTION

One embodiment of this invention will be described in detail hereinafterwith reference to the drawings.

FIG. 1 is a plan view showing an outline of a substrate treatingapparatus according to this embodiment. FIGS. 2 and 3 are schematic sideviews showing an arrangement of treating units included in the substratetreating apparatus. FIGS. 4 through 7 are views in vertical sectiontaken on lines a-a, b-b, c-c and d-d of FIG. 1, respectively.

This embodiment provides a substrate treating apparatus for formingresist film or the like on substrates (e.g. semiconductor wafers) W, anddeveloping exposed wafers W. This apparatus is divided into an indexersection (hereinafter called “ID section”) 1, a treating section 3 and aninterface section (hereinafter called “IF section”) 5. The ID section 1,treating section 3 and IF section 5 are arranged adjacent one another inthe stated order. An exposing machine EXP, which is an externalapparatus separate from this apparatus, is disposed adjacent the IFsection 5.

The ID section 1 takes wafers W out of each cassette C, which stores aplurality of wafers W, and deposits wafers W in the cassette C. The IDsection 1 has a cassette table 9 for receiving cassettes C, and an IDtransport mechanism T_(ID) for transporting wafers W to and from eachcassette C.

The treating section 3 carries out treatment for forming film on thewafers W and treatment for developing the wafers W. The treating section3 has a layered structure with a plurality of stories. In thisembodiment, the treating section 3 is divided into two, upper and lower,stories. The upper and lower stories have substantially the samestructure as described hereinafter. Each story includes a substratetreatment line for treating wafers W while transporting the wafers Wbetween the ID section 1 and IF section 5. The treatment carried out oneach story includes treatment for forming film on the wafers W andtreatment for developing the wafers W. FIG. 1 shows the upper story.

The treating section 3 has coating units 31 and heat-treating units 41arranged on each story. The coating units 31 apply a treating solutionto the wafers W. The heat-treating units 41 heat-treat the wafers W. Thecoating units 31 and heat-treating units 41 constitute a film formingsection for forming film on the wafers W. The treating section 3 hasalso developing units DEV for supplying a developer to the wafers W, andheat-treating units 42 for heat-treating the wafers W (to be describedhereinafter).

The treating section 3 includes four main transport mechanisms T₁, T₂,T₃ and T₄. The main transport mechanisms T₁ and T₂ are arranged on theupper story, while the main transport mechanisms T₃ and T₄ are arrangedon the lower story. Each of the main transport mechanisms T₁ and T₂transports wafers W to and from the coating units 31 and heat-treatingunits 41. Each of the main transport mechanisms T₃ and T₄ transportswafers W to and from the developing units DEV and so on. Further, themain transport mechanisms T₁ and T₂ transfer wafers W between thetransport mechanisms. Similarly, the main transport mechanisms T₃ and T₄transfer wafers W between the transport mechanisms. Each of the maintransport mechanisms T₁ and T₃ transfers wafers W to and from the IDtransport mechanism T_(ID).

The IF section 5 transports wafers W to and from the exposing machineEXP provided separately from the apparatus. The IF section 5 has IFtransport mechanisms T_(IF) for transporting wafers W. The IF transportmechanisms T_(IF) include an IF first transport mechanism T_(IFA) and anIF second transport mechanism T_(IFB). The IF transport mechanismsT_(IF) (first transport mechanism T_(IFA) and second transport mechanismT_(IFB)) correspond to the interface transport mechanisms in thisembodiment.

The construction of each component of this embodiment will be describedin greater detail hereinafter.

[ID Section 1]

The ID section 1 takes wafers W out of each cassette C, which stores aplurality of wafers W, and deposits wafers W in the cassette C. The IDsection 1 has a cassette table 9 for receiving cassettes C. The cassettetable 9 can receive four cassettes C as arranged in a row. The IDsection 1 has also an ID transport mechanism T_(ID). The ID transportmechanism T_(ID) transports wafers W to and from each cassette C, andtransports wafers W to and from receivers PASS₁ and PASS₃ to bedescribed hereinafter. The ID transport mechanism T_(ID) has a movablebase 21 for moving horizontally alongside the cassette table 9 in thedirection of arrangement of the cassettes C, a lift shaft 23 verticallyextendible and contractible relative to the movable base 21, and aholding arm 25 swivelable on the lift shaft 23, and extendible andretractable radially of the swivel motion, for holding a wafer W. The IDtransport mechanism T_(ID) corresponds to the indexer transportmechanism in this invention.

[Treating Section 3]

In this embodiment, the treating section 3 includes a plurality of (two)treating blocks Ba and Bb arranged side by side (in substantially thesame direction as the transport direction). Each of the treating blocksBa and Bb is vertically divided into two stories K. The upper story K1of the treating block Ba and the upper story K2 of the treating block Bbconstitute the upper story of the treating section 3 noted hereinbefore.Similarly, the lower story K3 of the treating block Ba and the lowerstory K4 of the treating block Bb constitute the lower story of thetreating section 3. The above main transport mechanism T₁ and varioustreating units corresponding thereto are arranged on the upper story K1of the treating block Ba, while the main transport mechanism T₃ andvarious treating units corresponding thereto are arranged on the lowerstory K3. Similarly, the main transport mechanism T₂ and varioustreating units corresponding thereto are arranged on the upper story K2of the treating block Bb, while the main transport mechanism T₄ andvarious treating units corresponding thereto are arranged on the lowerstory K4.

[Treating Section 3—Treating Block Ba]

The treating block Ba is disposed adjacent the ID section 1. ReceiversPASS₁ and PASS₃ for receiving wafers W are provided between the IDsection 1 and the respective stories K1 and K3 of the treating block Ba.The receiver PASS₁ receives, as placed thereon, wafers W passed betweenthe ID transport mechanism T_(ID) and the main transport mechanism T₁.Similarly, the receiver PASS₃ receives, as placed thereon, wafers Wpassed between the ID transport mechanism T_(ID) and the main transportmechanism T₃. Seen in a sectional view, the receiver PASS₁ is disposedat a height adjacent to a lower part of the upper story K2, while thereceiver PASS₃ is disposed at a height adjacent to an upper part of thelower story K3. Thus, the positions of receiver PASS₁ and receiver PASS₃are relatively close to each other for allowing the ID transportmechanism T_(ID) to move between the receiver PASS₁ and receiver PASS₃through using only a small amount of vertical movement.

Receivers PASS₂ and PASS₄ for receiving wafers W are provided for therespective stories K between the treating blocks Ba and Bb.Specifically, the receiver PASS₂ is disposed between the story K1 andstory K2, and the receiver PASS₄ between the story K3 and story K4. Themain transport mechanisms T₁ and T₂ transfer wafers W through thereceiver PASS₂, and the main transport mechanisms T₃ and T₄ through thereceiver PASS₄.

The receiver PASS₁ includes a plurality of receivers (two in thisembodiment). These receivers PASS₁ are arranged vertically adjacent toeach other. Similarly, each of the receivers PASS₂-PASS₄, and each ofreceivers PASS₅ and PASS₆ to be described hereinafter, includes aplurality of receivers (two in this embodiment) arranged verticallyadjacent to each other.

One of the receivers PASS constituting each pair of receiversPASS₁-PASS₆ is selected according to a direction for transferring wafersW.

The receiver PASS₁, for example, has two receivers PASS_(1A) andPASS_(1B) arranged vertically adjacent to each other. One of thesereceivers PASS_(1A) receives wafers W passed from the ID transportmechanism T_(ID) to the main transport mechanism T₁. The other receiverPASS_(1B) receives wafers W passed from the main transport mechanism T₁to the ID transport mechanism T_(ID).

The receiver PASS₂, for example, has two receivers PASS_(2A) andPASS_(2B) arranged vertically adjacent to each other. One of thesereceivers PASS_(2A) receives wafers W passed from the main transportmechanism T₁ to the main transport mechanism T₂. The other receiverPASS_(2B) receives wafers W passed from the main transport mechanism T₂to the main transport mechanism T₁. In this case, the wafers W placed onone of the receivers PASS_(2A) are wafers W having film formed in thefilm forming section (coating units 31 and heat-treating units 41) onthe story K1. The wafers W placed on the other receiver PASS_(2B) arewafers W developed in the developing units DEV on the story K2. This isthe case also with the receiver PASS₄.

Each of the receivers PASS₁-PASS₆ has a plurality of support pinsprojecting therefrom, for receiving a wafer W in a substantiallyhorizontal position on these support pins. Each of the receiversPASS₁-PASS₆ has also a sensor Sp for detecting presence or absence of awafer W. Detecting signals of each sensor Sp are inputted to a controlsection 90 described hereinafter. Based on the detection signals of eachsensor Sp, the control section 90 determines whether or not a wafer W isplaced on the receiver PASS, and controls the transport mechanisms intransferring wafers W through the receiver PASS. The receiver PASS₂ andreceiver PASS₄ correspond to the first receiver in this invention. Thesensors Sp for detecting wafers W placed on the receivers PASS₂ andPASS₄ correspond to the first detector in this invention.

Further, buffers BF2 and BF4 are provided for the respective receiversPASS₂ and PASS₄ between the treating blocks Ba and Bb. The buffers BF2and BF4 are used to hold wafers W temporarily. In this embodiment, whena wafer W cannot be placed on each receiver PASS, the wafer W is placedon the corresponding buffer BF temporarily. That is, usually or during anormal operation, the wafers W are placed only on the receivers PASS,and the wafers W are not placed on the buffers BF.

The buffers BF2 and BF4 are arranged adjacent the receivers PASS₂ andPASS₄, respectively. In this embodiment, the buffer BF2 is stacked underthe receiver PASS₂, and the buffer BF4 under the receiver PASS₄.

The number of wafers W that can be accommodated in each of the buffersBF2 and BF4, preferably, is equal to or larger than the number ofcoating units 31 provided on each story K1 or K3. Where, for example,the story K1 has two resist film coating units RESIST₁ and twoanti-reflection film coating units BARC₁, the buffer BF2 can accommodateat least four wafers W which corresponds to the total number of coatingunits. More preferably, the number of wafers W that can be accommodatedin each of the buffers BF2 and BF4 is equal to or larger than the numberof wafers W that can be treated simultaneously in the film formingsection on the story K1 or K3.

In this embodiment, as shown in FIG. 4, each of the buffers BF2 and BF4can accommodate five wafers W.

Each of the buffers BF2 and BF4 has shelves for storing wafers W inmultiple stages, and is open at opposite ends facing the main transportmechanism T₁ and main transport mechanism T₂. Thus, both of the maintransport mechanism T₁ and main transport mechanism T₂ can depositwafers W on the shelves, and fetch wafers W from the shelves. Thebuffers BF2 and BF4 are not limited to the above construction. As longas they can receive wafers W temporarily, the buffers BF2 and BF4 mayhold wafers W in any positions, e.g. peripheral positions or at thelower surfaces. For example, each buffer BF may have a plurality ofprojecting support pins like the receivers PASS, for supporting wafers Win a substantially horizontal position.

Each of the buffers BF2 and BF4, and buffers BFIF described hereinafter,has a sensor (not shown) for detecting presence or absence of wafers Wplaced thereon. Detection signals of each sensor is inputted to thecontrol section 90 described hereinafter. Based on the detection signalsof each sensor, the control section 90 determines whether or not wafersW are placed on the buffer BF, and controls substrate transport of thecorresponding transport mechanisms. Each of the buffers BF2 and BF4corresponds to the first buffer in this invention. Each sensor fordetecting wafers W placed on the buffer BF2 or BF4 corresponds to thesecond detector in this invention.

The story K1 will now be described. The main transport mechanism T₁ ismovable in a transporting space A₁ extending substantially through thecenter of the story K1 and parallel to the direction of transport. Thetreating units on the story K1 are divided broadly into coating units 31for applying a treating solution to wafers W, and heat-treating units 41for heat-treating the wafers W. The coating units 31 are arranged on oneside of the transporting space A₁, while the heat-treating units 41 arearranged on the other side thereof. The coating units 31 andheat-treating units 41 constitute the film forming section notedhereinbefore.

The coating units 31 are arranged vertically and horizontally, eachfacing the transporting space A₁. In this embodiment, four coating units31 in total are arranged in two columns and two rows.

The coating units 31 include anti-reflection film coating units BARC forforming anti-reflection film on the wafers W, and resist film coatingunits RESIST for forming resist film on the wafers W (i.e. carrying outresist film forming treatment).

The anti-reflection film coating units BARC apply a treating solutionfor anti-reflection film to the wafers W. The resist film coating unitsRESIST apply a resist film material to the wafers W. The plurality of(two) anti-reflection film coating units BARC are arranged atsubstantially the same height in the lower row. The plurality of resistfilm coating units RESIST are arranged at substantially the same heightin the upper row. No dividing wall or partition is provided between theanti-reflection film coating units BARC. That is, all theanti-reflection film coating units BARC are only housed in a commonchamber, and the atmosphere around each anti-reflection film coatingunit BARC is not blocked off (i.e. is in communication). Similarly, theatmosphere around each resist film coating unit RESIST is not blockedoff.

Reference is made to FIGS. 8A and 8B. FIG. 8A is a plan view of thecoating units 31. FIG. 8B is a sectional view of a coating unit 31. Eachcoating unit 31 includes a spin holder 32 for holding and spinning awafer W, a cup 33 surrounding the wafer W, and a supply device 34 forsupplying a treating solution to the wafer W.

The supply device 34 includes a plurality of nozzles 35, a gripper 36for gripping one of the nozzles 35, and a nozzle moving mechanism 37 formoving the gripper 36 to move one of the nozzles 35 between a treatingposition above the wafer W and a standby position away from above thewafer W. Each nozzle 35 has one end of a treating solution pipe 38connected thereto. The treating solution pipe 38 is arranged movable(flexible) to permit movement of the nozzle 35 between the standbyposition and treating position. The other end of each treating solutionpipe 38 is connected to a treating solution source (not shown).Specifically, in the case of anti-reflection film coating units BARC,the treating solution sources supply different types of treatingsolution for anti-reflection film to the respective nozzles 35. In thecase of resist film coating units RESIST, the treating solution sourcessupply different types of resist film material to the respective nozzles35.

The nozzle moving mechanism 37 has first guide rails 37 a and a secondguide rail 37 b. The first guide rails 37 a are arranged parallel toeach other and opposed to each other across the two cups 33 arrangedsideways. The second guide rail 37 b is slidably supported by the twofirst guide rails 37 a and disposed above the two cups 33. The gripper36 is slidably supported by the second guide rail 37 b. The first guiderails 37 a and second guide rail 37 b take guiding action substantiallyhorizontally and in directions substantially perpendicular to eachother. The nozzle moving mechanism 37 further includes drive members(not shown) for sliding the second guide rail 37 b, and sliding thegripper 36. The drive members are operable to move the nozzle 35 grippedby the gripper 36 to the treating positions above the two spin holders32.

The plurality of heat-treating units 41 are arranged vertically andhorizontally, each facing the transporting space A₁. In this embodiment,three heat-treating units 41 can be arranged horizontally, and fiveheat-treating units 41 can be stacked vertically. Each heat-treatingunit 41 has a plate 43 for receiving a wafer W. The heat-treating units41 include cooling units CP for cooling wafers W, heating and coolingunits PHP for carrying out heating and cooling treatments continually,and adhesion units AHL for heat-treating wafers W in an atmosphere ofhexamethyldisilazane (HMDS) vapor in order to promote adhesion ofcoating film to the wafers W. As shown in FIG. 5, each heating andcooling unit PHP has two plates 43, and a local transport mechanism (notshown) for moving a wafer W between the two plates 43. The various typesof heat-treating units CP, PHP and AHL are arranged in appropriatepositions.

The main transport mechanism T₁ will be described specifically.Reference is made to FIG. 9. FIG. 9 is a perspective view of the maintransport mechanism T₁. The main transport mechanism T₁ has two thirdguide rails 51 for providing vertical guidance, and a fourth guide rail52 for providing horizontal guidance. The third guide rails 51 are fixedopposite each other at one side of the transporting space A₁. In thisembodiment, the third guide rails 51 are arranged at the side adjacentthe coating units 31. The fourth guide rail 52 is slidably attached tothe third guide rails 51. The fourth guide rail 52 has a base 53slidably attached thereto. The base 53 extends transversely,substantially to the center of the transporting space A₁. Further, drivemembers (not shown) are provided for vertically moving the fourth guiderail 52, and horizontally moving the base 53. The drive members areoperable to move the base 53 to positions for accessing the coatingunits 31 and heat-treating units 41 arranged vertically andhorizontally.

The base 53 has a turntable 55 rotatable about a vertical axis Q. Theturntable 55 has two holding arms 57 a and 57 b horizontally movablyattached thereto for holding wafers W, respectively. The two holdingarms 57 a and 57 b are arranged vertically close to each other. Further,drive members (not shown) are provided for rotating the turntable 55,and moving the holding arms 57 a and 57 b. The drive members areoperable to move the turntable 55 to positions opposed to the coatingunits 31, heat-treating units 41, receivers PASS₁ and PASS₂ and bufferBF2, and to extend and retract the holding arms 57 a and 57 b to andfrom the coating units 31 and so on.

The story K3 will be described next. Like reference numerals are used toidentify like parts which are the same as in the story K1, and will notbe described again. The layout (arrangement) in plan view of the maintransport mechanism T₃ and various treating units on the story K3 issubstantially the same as on the story K1. Thus, the arrangement of thevarious treating units of the story K3 as seen from the main transportmechanism T₃ is substantially the same as the arrangement of the varioustreating units of the story K1 as seen from the main transport mechanismT₁. The coating units 31 and heat-treating units 41 of the story K3 arestacked under the coating units 31 and heat-treating units 41 of thestory K1, respectively.

In the following description, when distinguishing the resist filmcoating units RESIST in the stories K1 and K3, subscripts “1” and “3”will be affixed (for example, the resist film coating units RESIST inthe story K1 will be referred to as “resist film coating unitsRESIST₁”).

The other aspects of the treating block Ba will be described. As shownin FIGS. 5 and 6, each of the transporting spaces A₁ and A₃ has a firstblowout unit 61 for blowing out a clean gas, and an exhaust unit 62 forsucking the gas. Each of the first blowout unit 61 and exhaust unit 62is in the form of a flat box having substantially the same area as thetransporting space A₁ in plan view. Each of the first blowout unit 61and exhaust unit 62 has first blowout openings 61 a or exhaust openings62 a formed in one surface thereof. In this embodiment, the firstblowout openings 61 a or exhaust openings 62 a are in the form ofnumerous small bores f (see FIG. 9). The first blowout units 61 arearranged over the transporting spaces A₁ and A₃ with the first blowoutopenings 61 a directed downward. The exhaust units 62 are arranged underthe transporting spaces A₁ and A₃ with the exhaust openings 62 adirected upward. The atmosphere in the transporting space A₁ and theatmosphere in the transporting space A₃ are blocked off by the exhaustunit 62 of the transporting space A₁ and the first blowout unit 61 ofthe transporting space A₃. Thus, each of the stories K1 and K3 has theatmosphere blocked off from the other.

Referring to FIG. 5, the first blowout units 61 of the transportingspaces A₁ and A₃ are connected to a common, first gas supply pipe 63.The first gas supply pipe 63 extends laterally of the receivers PASS₂and PASS₄ from an upper position of the transporting space A₁ to a lowerposition of the transporting space A₃, and is bent below thetransporting space A₃ to extend horizontally. The other end of the firstgas supply pipe 63 is connected to a gas source not shown. Similarly,the exhaust units 62 of the transporting spaces A₁ and A₃ are connectedto a common, first gas exhaust pipe 64. The first gas exhaust pipe 64extends laterally of the receivers PASS₂ and PASS₄ from a lower positionof the transporting space A₁ to a lower position of the transportingspace A₃, and is bent below the transporting space A₂ to extendhorizontally. As the gas is blown out of each first blowout opening 61 aand sucked and exhausted through each exhaust opening 62 a of thetransporting spaces A₁ and A₃, gas currents are formed to flow from topto bottom of the transporting spaces A₁ and A₃, thereby keeping each ofthe transporting spaces A₁ and A₃ in a clean state.

As shown in FIGS. 1, 6 and 8A, each coating unit 31 of the stories K1and K3 has a pit portion PS extending vertically. The pit portion PSaccommodates a second gas supply pipe 65 extending vertically forsupplying the clean gas, and a second gas exhaust pipe 66 extendingvertically for exhausting the gas. Each of the second gas supply pipe 65and second gas exhaust pipe 66 branches at a predetermined height ineach coating unit 31 to extend substantially horizontally from the pitportion PS. A plurality of branches of the second gas supply pipe 65 areconnected to second blowout units 67 for blowing out the gas downward. Aplurality of branches of the second gas exhaust pipe 66 are connectedfor communication to the bottoms of the respective cups 33. The otherend of the second gas supply pipe 65 is connected to the first gassupply pipe 63 below the story K3. The other end of the second gasexhaust pipe 66 is connected to the first gas exhaust pipe 64 below thestory K3. As the gas is blown out of the second blowout units 67 andexhausted through the second exhaust pipes 62 a, the atmosphere insideeach cup 33 is constantly maintained clean, thereby allowing forexcellent treatment of the wafer W held by the spin holder 32.

The pit portions PS further accommodate piping of the treatingsolutions, electric wiring and the like (not shown). Thus, with the pitportions PS accommodating the piping and electric wiring provided forthe coating units 31 of the stories K1 and K3, the piping and electricwiring can be reduced in length.

The treating block Ba has one housing 75 for accommodating the maintransport mechanisms T₁ and T₃, coating units 31 and heat-treating units41 described hereinbefore. The treating block Bb described hereinafteralso has a housing 75 for accommodating the main transport mechanisms T₂and T₄ and the various treating units of the treating block Bb. Thehousing 75 of the treating block Ba and the housing 75 of the treatingblock Bb are separate entities. Thus, with each of the treating blocksBa and Bb having the housing 75 accommodating the main transportmechanisms T and various treating units en bloc, the treating section 3may be manufactured and assembled simply. The treating block Bacorresponds to the resist film coating block in this invention. The maintransport mechanisms T₁ and T₃ correspond to the first main transportmechanism in this invention.

[Treating Section 3—Treating Block Bb]

The treating block Bb is disposed adjacent the IF section 5. The storyK2 will be described. Like reference numerals are used to identify likeparts which are the same as in the story K1 and will not be describedagain. The story K2 has a transporting space A₂ formed as an extensionof the transporting space A₁.

The treating units on the story K2 are developing units DEV fordeveloping wafers W, heat-treating units 42 for heat-treating the wafersW, and an edge exposing unit EEW for exposing peripheral regions of thewafers W. The developing units DEV are arranged at one side of thetransporting space A₂, and the heat-treating units 42 and edge exposingunit EEW are arranged at the other side of the transporting space A₂.Preferably, the developing units DEV are arranged at the same side asthe coating units 31. It is also preferable that the heat-treating units42 and edge exposing unit EEW are arranged in the same row as theheat-treating units 41. The developing units DEV and heat-treating units42 constitute a developing section for developing wafers W.

The number of developing units DEV is four, and sets of two units DEVarranged horizontally along the transporting space A₂ are stacked oneover the other. As shown in FIGS. 1 and 6, each developing unit DEVincludes a spin holder 77 for holding and spinning a wafer W, and a cup79 surrounding the wafer W. The two developing units DEV arranged at thelower level are not separated from each other by a partition wall or thelike. A supply device 81 is provided for supplying developers to the twodeveloping units DEV. The supply device 81 includes two slit nozzles 81a having a slit or a row of small bores for delivering the developers.The slit or row of small bores, preferably, has a length correspondingto the diameter of wafer W. Preferably, the two slit nozzles 81 a arearranged to deliver developers of different types or concentrations. Thesupply device 81 further includes a moving mechanism 81 b for movingeach slit nozzle 81 a. Thus, the slit nozzles 81 a are movable,respectively, over the two spin holders 77 juxtaposed sideways.

The plurality of heat-treating units 42 are arranged sideways along thetransporting space A₂, and stacked one over the other. The heat-treatingunits 42 include heating units HP for heating wafers W, cooling units CPfor cooling wafers W, and heating and cooling units PHP for successivelycarrying out heating treatment and cooling treatment.

The plurality of heating and cooling units PHP are vertically stacked inthe column closest to the IF section 5, each having one side facing theIF section 5. The heating and cooling units PHP on the story K2 havetransport ports formed in the sides thereof for passage of wafers W. IFtransport mechanisms T_(IF) to be described hereinafter transport wafersW through the above transport ports to the heating and cooling unitsPHP. The heating and cooling units PHP arranged on the story K2 carryout post-exposure baking (PEB) treatment for exposed wafers W.

The single edge exposing unit EEW is disposed in a predeterminedposition. The edge exposing unit EEW includes a spin holder (not shown)for holding and spinning a wafer W, and a light emitter (not shown) forexposing edges of the wafer W held by the spin holder.

The receiver PASS₅ is formed on top of the heating and cooling units PHPon the story K2. Through the receiver PASS₅, the main transportmechanism T₂ and IF transport mechanisms T_(IF) to be describedhereinafter transfer wafers W.

The main transport mechanism T₂ is disposed substantially centrally ofthe transporting space A₂ in plan view. The main transport mechanism T₂has the same construction as the main transport mechanism T₁. The maintransport mechanism T₂ transports wafers W to and from the receiverPASS₂, various heat-treating units 42, edge exposing unit EEW andreceiver PASS₅.

The story K4 will be described briefly. The relationship in constructionbetween story K2 and story K4 is similar to that between stories K1 andK3. The treating units U on the story K4 are developing units DEV,heat-treating units 42 and an edge exposing unit EEW. The heat-treatingunits 42 on the story K4 include heating units HP, cooling units CP andheating and cooling units PHP. The receiver PASS₆ is formed on top ofthe heating and cooling units PHP on the story K4. The main transportmechanism T₄ and IF transport mechanisms T_(IF) described hereinaftertransfer wafers W through the receiver PASS₆. The heating and coolingunits PHP on the story K4 also correspond to the PEB units in thisinvention.

In the following description, when distinguishing the developing unitsDEV, edge exposing units EEW and so on provided on the stories K2 andK4, subscripts “2” and “4” will be affixed (for example, the heatingunits HP on the story K2 will be referred to as “heating units HP₂”).

Each of the transporting spaces A₂ and A4 of the stories K2 and K4 alsohas constructions corresponding to the first blowout unit 61 and exhaustunit 62. Each developing unit DEV of the stories K2 and K4 also hasconstructions corresponding to the second blowout unit 67 and second gasexhaust pipe 66.

The treating block Bb corresponds to the developing block in thisinvention. Each of the main transport mechanism T₂ and main transportmechanism T₄ corresponds to the second main transport mechanism and tothe other main transport mechanism in this invention. Each of thereceiver PASS₅ and receiver PASS₆ corresponds to the second receiver inthis invention.

The IF section 5 transfers wafers W between the treating section 3 (moreparticularly, the stories K2 and K4 of the treating block Bb) and theexposing machine EXP. The IF section 5 has IF transport mechanismsT_(IF) for transporting wafers W. IF transport mechanisms T_(IF) includean IF first transport mechanism T_(IFA) and an IF second transportmechanism T_(IFB) that can transfer wafers W to and from the transportmechanisms. IF first transport mechanism T_(IFA) transports wafers W toand from the stories K2 and K4. In this embodiment, as describedhereinbefore, IF first transport mechanism T_(IFA) transports wafers Wto and from the receivers PASS₅ and PASS₆ on the stories K2 and K4, andto and from the heating and cooling units PHP on the stories K2 and K4.IF second transport mechanism T_(IFB) transports wafers W to and fromthe exposing machine EXP. IF transport mechanisms T_(IF) correspond tothe interface transport mechanisms in this invention.

As shown in FIG. 1, IF first transport mechanism T_(IFA) and IF secondtransport mechanism T_(IFB) are arranged in a transverse directionsubstantially perpendicular to the direction of arrangement of the maintransport mechanisms T on each story. IF first transport mechanismT_(IFA) is disposed at the side where the heat-treating units 42 and soon of the treating block Bb are located. IF second transport mechanismT_(IFB) is disposed at the side where the developing units DEV of thetreating block Bb are located.

Stacked in multiples stages between IF first and second transportmechanisms T_(IFA) and T_(IFB) are a receiver PASS-CP for receiving andcooling wafers W, a receiver PASS₇ for receiving wafers W, and buffersBFIF for temporarily storing wafers W. The buffers BFIF are divided intoa send buffer BF_(IFS) for temporarily storing wafers W to be sent tothe exposing machine EXP, and a return buffer BF_(IFR) for temporarilystoring wafers W to be returned to the treating section 3. The returnbuffer BF_(IFR) stores wafers W having received post-exposure baking(PEB) treatment. The send buffer BF_(IFS) can accommodate five wafers W.The return buffer BF_(IFR) can accommodate eight wafers W whichcorresponds in number to the total of heating and cooling units PHPwhich carry out the post-exposure baking (PEB) treatment.

IF first and second transport mechanisms T_(IFA) and T_(IFB) transferwafers W through the receiver PASS-CP and receiver PASS. The buffersBFIF are accessed exclusively by IF first transport mechanism T_(IFA).The return buffer BF_(IFR) corresponds to the second buffer in thisinvention.

As shown in FIG. 7, IF first transport mechanism T_(IFA) includes afixed base 83, lift shafts 85 vertically extendible and contractiblerelative to the base 83, and a holding arm 87 swivelable on the liftshafts 85, and extendible and retractable radially of the swivel motion,for holding a wafer W. IF second transport mechanism T_(IFB) also has abase 83, lift shafts 85 and a holding arm 87.

A control system of this apparatus will be described next. FIG. 10 is acontrol block diagram of the substrate treating apparatus according tothe invention. As shown, the control section 90 of this apparatusincludes a main controller 91 and first to seventh controllers 93, 94,95, 96, 97, 98 and 99.

The main controller 91 performs overall control of the first to seventhcontrollers 93-99. Further, the main controller 91 can communicatethrough a host computer with an exposing machine controller provided forthe exposing machine EXP. The first controller 93 controls substratetransport by the ID transport mechanism T_(ID). The second controller 94controls substrate transport by the main transport mechanism T₁, andsubstrate treatment in the resist film coating units RESIST₁,anti-reflection film coating units BARC₁, cooling units CP₁, heating andcooling units PHP₁ and adhesion units AHL₁. The third controller 95controls substrate transport by the main transport mechanism T₂, andsubstrate treatment in the edge exposing unit EEW₂, developing unitsDEV₂, heating units HP₂ and cooling units CP₂. The controls by thefourth and fifth controllers 96 and 97 correspond to those by the secondand third controllers 94 and 95, respectively. The sixth controller 98controls substrate transport by IF first transport mechanism T_(IFA),and substrate treatment in the heating and cooling units PHP₂ and PHP₄.The seventh controller 99 controls substrate transport by IF secondtransport mechanism T_(IFB). The first to seventh controllers 93-99carry out the controls independently of one another.

Each of the main controller 91 and the first to seventh controllers93-99 is realized by a central processing unit (CPU) which performsvarious processes, a RAM (Random Access Memory) used as the workspacefor operation processes, and a storage medium such as a fixed disk forstoring a variety of information including a predetermined processingrecipe (processing program).

Next, operation of the substrate treating apparatus in this embodimentwill be described. FIG. 11 is a flow chart of a series of treatments ofwafers W, indicating the treating units and receivers to which thewafers W are transported in order. FIG. 12 is a view schematicallyshowing operations repeated by each transport mechanism, and specifyingan order of treating units, receivers and cassettes accessed by thetransport mechanisms. FIGS. 11 and 12 show an example of ordinaryoperation in which the transport mechanisms can transfer wafers Wthrough the receivers PASS. The following description will be madeseparately for each transport mechanism. Further, regarding the maintransport mechanisms T₁-T₄ and IF transport mechanisms T_(IF), anexample of operation in which wafers W cannot be placed on the receiversPASS will be described in addition to the example of normal operation.

[ID Transport Mechanism T_(ID)]

The ID transport mechanism T_(ID) moves to a position opposed to one ofthe cassettes C, holds with the holding arm 25 a wafer W to be treatedand takes the wafer W out of the cassette C. The ID transport mechanismT_(ID) swivels the holding arm 25, vertically moves the lift shaft 23,moves to a position opposed to the receiver PASS₁, and places the waferW on the receiver PASS_(1A) (which corresponds to step S1 a in FIG. 11;only step numbers will be indicated hereinafter). At this time, a waferW usually is present on the receiver PASS_(1B), and the ID transportmechanism T_(ID) receives this wafer W and stores it in a cassette C(step S23). When there is no wafer W on the receiver PASS_(1B), step S23is omitted. Then, the ID transport mechanism T_(ID) accesses thecassette C, and transports a wafer W from the cassette C to the receiverPASS_(3A) (step S1 b). Here again, if a wafer W is present on thereceiver PASS_(3B), the ID transport mechanism T_(ID) will store thiswafer W in a cassette C (step S23). The ID transport mechanism T_(ID)repeats the above operation.

This operation of the ID transport mechanism T_(ID) is controlled by thefirst controller 93. As a result, the wafers W in the cassette C are fedto the story K1, and the wafers W delivered from the story K1 are storedin the cassette C. Similarly, the wafers W in the cassette C are fed tothe story K3, and the wafers W delivered from the story K3 are stored inthe cassette C.

[Main Transport Mechanisms T₁, T₃]

Since operation of the main transport mechanism T₃ is substantially thesame as operation of the main transport mechanism T₁, only the maintransport mechanism T₁ will be described. The main transport mechanismT₁ moves to a position opposed to the receiver PASS₁. At this time, themain transport mechanism T₁ holds, on one holding arm 57 (e.g. 57 b), awafer W received immediately before from the receiver PASS_(2B). Themain transport mechanism T₁ places this wafer W on the receiverPASS_(1B) (step S22), and holds the wafer W present on the receiverPASS_(1A) with the other holding arm 57 (e.g. 57 a).

The main transport mechanism T₁ accesses a predetermined one of thecooling units CP₁. There is a different wafer W having already receiveda predetermined heat treatment (cooling) in the cooling unit CP₁. Themain transport mechanism T₁ holds the different wafer W with theunloaded holding arm 57 (holding no wafer W), takes it out of thecooling unit CP₁, and loads into the cooling unit CP₁ the wafer W havingbeen received from the receiver PASS_(1A). Then, the main transportmechanism T₁, holding the cooled wafer W, moves to one of theanti-reflection film coating units BARC₁. The cooling unit CP₁ startsheat treatment (cooling) of the wafer W loaded therein (step S2). Thisheat treatment (cooling) will have been finished by the time the maintransport mechanism T₁ accesses this cooling unit CP₁ next time. Thefollowing description assumes that wafers W having receivedpredetermined treatments are present also in the other, differentheat-treating units 41 and coating units 31 when the main transportmechanism T₁ makes access thereto.

Accessing the anti-reflection film coating unit BARC₁, the maintransport mechanism T₁ takes a wafer W having anti-reflection filmformed thereon from the anti-reflection film coating unit BARC₁, andplaces the cooled wafer W on the spin holder 32 of the anti-reflectionfilm coating unit BARC₁. Then, the main transport mechanism T₁, holdingthe wafer W having anti-reflection film formed thereon, moves to one ofthe heating and cooling units PHP₁. The anti-reflection film coatingunit BARC₁ starts treatment of the wafer W placed on the spin holder 32(step S3).

Specifically, the spin holder 32 spins the wafer W in horizontalposture, the gripper 26 grips one of the nozzles 35, the nozzle movingmechanism 37 moves the gripped nozzle 35 to a position above the waferW, and the treating solution for anti-reflection film is supplied fromthe nozzle 35 to the wafer W. The treating solution supplied spreads allover the wafer W, and is scattered away from the wafer W. The cup 33collects the scattering treating solution. In this way, the treatment iscarried out for forming anti-reflection film on the wafer W.

Accessing the heating and cooling unit PHP₁, the main transportmechanism T₁ takes a wafer W having received heat treatment out of theheating and cooling unit PHP₁, and loads the wafer W havinganti-reflection film formed thereon into the heating and cooling unitPHP₁. Then, the main transport mechanism T₁, holding the wafer W takenout of the heating and cooling unit PHP₁, moves to one of the coolingunits CP₁. The heating and cooling unit PHP₁ receives a wafer Wsuccessively on the two plates 43, to heat the wafer W on one of theplates 43 and then to cool the wafer W on the other plate 43 (step S4).

Having moved to the cooling unit CP₁, the main transport mechanism T₁takes a wafer W out of the cooling unit CP₁, and loads the wafer W heldby the transport mechanism T₁ into the cooling unit CP₁. The coolingunit CP₁ cools the wafer W loaded therein (step S5).

Then, the main transport mechanism T₁ moves to one of the resist filmcoating units RESIST₁. The main transport mechanism T₁ takes a wafer Whaving resist film formed thereon from the resist film coating unitRESIST₁, and loads the wafer W held by the main transport mechanism T₁into the resist film coating unit RESIST₁. The resist film coating unitRESIST₁ supplies the resist film material while spinning the wafer Wloaded therein, to form resist film on the wafer W (step S6).

The main transport mechanism T₁ further moves to one of the heating andcooling units PHP₁ and one of the cooling units CP₁. The main transportmechanism T₁ loads the wafer W having resist film formed thereon intothe heating and cooling unit PHP₁, transfers a wafer W treated in theheating and cooling unit PHP₁ to the cooling unit CP₁, and receives awafer W treated in the cooling unit CP₁. The heating and cooling unitPHP₁ and cooling unit CP₁ carry out predetermined treatments of newlyloaded wafers W, respectively (steps S7 and S8).

The main transport mechanism T₁ moves to the receiver PASS₂, places thewafer W it is holding on the receiver PASS_(2A) (step S9), and receivesa wafer W present on the receiver PASS_(2A) (step S21).

Subsequently, the main transport mechanism T₁ accesses the receiverPASS₁ again, and repeats the above operation. This operation iscontrolled by the second controller 94. As a result, the main transportmechanism T₁ receives a wafer W from the receiver PASS₁ and transportsthe wafer W to a predetermined treating unit (a cooling unit CP₁ in thisembodiment), and takes a treated wafer W from this treating unit.Subsequently, the main transport mechanism T₁ transports the wafer Wtaken out to a different treating unit, and takes a treated wafer W fromthe different treating unit. In this way, the treatment is carried outin parallel for a plurality of wafers W by transferring a treated waferW from each treating unit to a new treating unit. Starting with a waferW first placed on the receiver PASS₁, the wafers W are successivelyplaced on the receiver PASS₂ to be fed to the story K2. Similarly, thewafers W are placed on the receiver PASS₁ in the order of placement onthe receiver PASS₂, to be fed to the ID section 1.

Next, operations taking place when the main transport mechanism T₁cannot place the wafer W on the receiver PASS₂ in the above step S9 willbe described.

A situation where a wafer W cannot be placed on the receiver PASS₂ maybe caused by the receiver PASS₂, e.g. due to a different wafer W presenton the receiver PASS₂. Apart from this, the cause may lie in a differentcomponent such as the main transport mechanism T₁, various treatingunits or controller 90. The wafer cannot be placed on the receiver PASS₂when the main transport mechanism T₁ fails to operate properly, when thecontrol section 90 does not permit the main transport mechanism T₁ toplace the wafer W on the receiver PASS₂, or when the control section 90fails to control properly. In this specification, a time when a wafer Wcannot be placed on a receiver PASS will be called an abnormal time asappropriate.

Whether a wafer W can be placed on the receiver PASS₂ is determined bythe second controller 94. The second controller 94 determines from aresult of detection by the sensor Sp of the receiver PASS₂ whetheranother wafer W is present on the receiver PASS₂. When another wafer Wis present on the receiver PASS₂, the second controller 94 determinesthat the further wafer W cannot be placed on the receiver PASS₂. Sincethe result of detection by the sensor Sp of the receiver PASS₂ isinputted also to the third controller 95, the same determination is madealso by the third controller 95.

When the second controller 94 determines that the wafer W cannot beplaced on the receiver PASS₂ in step S9, the main transport mechanism T₁moves to the position opposed to the buffer BF2, and temporarily placesthe wafer W it holds on the buffer BF2. Once the wafer W is placed onthe buffer BF2, the operation shifts to the ordinary substratetransporting operation of step S21 noted hereinbefore. Specifically, themain transport mechanism T₁ receives a wafer W from the receiverPASS_(2B) (step S21), and places the received wafer W on the receiverPASS₁ (step S22).

After further repeating the series of operations, when a wafer W cannotbe placed on the receiver PASS₂ in step S9 again, the main transportmechanism T₁ temporarily places the wafer W on the buffer BF2. Thebuffer BF2 can accommodate five wafers W in this embodiment. Even if thestate where wafers W cannot placed on the receiver PASS₂ continues, themain transport mechanism T₁ can repeat the series of operations at leastfive times. This operation of the main transport mechanism T₁ is alsocontrolled by the second controller 94.

Thus, even when a wafer W cannot be placed on the receiver PASS₂, themain transport mechanism T₁, by placing the wafer W on the buffer BF2,can promptly shift to operation for transporting other wafers W.Therefore, the main transport mechanism T₁ can continue the transportingoperation in steps S21 et seq. Since the buffer BF2 is disposed adjacentthe receiver PASS₂, the time taken in the operation for placing a waferW on the buffer BF2 is almost the same as the time taken in theoperation (step S9) for placing a wafer W on the receiver PASS₂.Therefore, the transporting steps, steps S21 et seq., may be resumedafter step S9 without delay, compared with a schedule for the normaloperation (specifically, a schedule for the case where the wafer can beplaced on the receiver PASS₂).

Since the buffer BF2 can accommodate five wafers W, even if it becomesimpossible for the main transport mechanism T₁ to place a wafer W on thereceiver PASS₂ while all of the four coating units 31 are treatingwafers, the wafers W can be transported successively from the coatingunits 31 to the heat-treating units 41. It is therefore possible tostart heat treatment of each wafer W as scheduled for a normaloperation. Thus, even when a wafer W cannot be placed on the receiverPASS₂, it is possible to prevent lowering the quality of treatment forforming film on the wafers W.

[Main Transport Mechanisms T_(z), T₄]

Since operation of the main transport mechanism T₄ is substantially thesame as operation of the main transport mechanism T₂, only the maintransport mechanism T₂ will be described. The main transport mechanismT₂ moves to a position opposed to the receiver PASS₂. At this time, themain transport mechanism T₂ holds a wafer W received from a cooling unitCP₂ accessed immediately before. The main transport mechanism T₂ placesthis wafer W on the receiver PASS_(2B) (step S21), and holds the wafer Wpresent on the receiver PASS_(2A) (step S9).

The main transport mechanism T₂ accesses the edge exposing unit EEW₂.The main transport mechanism T₂ receives a wafer W having received apredetermined treatment in the edge exposing unit EEW₂, and loads thecooled wafer W into the edge exposing unit EEW₂. While spinning thewafer W loaded therein, the edge exposing unit EEW₂ irradiatesperipheral regions of the wafer W with light from the light emitter notshown, thereby exposing the peripheral regions of the wafer W (stepS10).

The main transport mechanism T₂, holding the wafer W received from theedge exposing unit EEW₂, accesses the receiver PASS₅. The main transportmechanism T₂ places the wafer W on the receiver PASS_(5A) (step S11),and holds a wafer W present on the receiver PASS_(5B) (step S16).

The main transport mechanism T₂ moves to one of the cooling units CP₂,and replaces a wafer W in the cooling unit CP₂ with the wafer W held bythe main transport mechanism T₂. The main transport mechanism T₂ holdsthe wafer W having received cooling treatment, and accesses one of thedeveloping units DEV₂. The cooling unit CP₂ starts treatment of thenewly loaded wafer W (step S17).

The main transport mechanism T₂ takes a developed wafer W from thedeveloping unit DEV₂, and places the cooled wafer W on the spin holder77 of the developing unit DEV₂. The developing unit DEV₂ develops thewafer W placed on the spin holder 77 (step S18). Specifically, while thespin holder 77 spins the wafer W in horizontal posture, the developer issupplied from one of the slit nozzles 81 a to the wafer W, therebydeveloping the wafer W.

The main transport mechanism T₂ holds the developed wafer W, andaccesses one of the heating units HP₂. The main transport mechanism T₂takes a wafer W out of the heating unit HP₂, and loads the wafer W it isholding into the heating unit HP₂. Then, the main transport mechanism T₂transports the wafer W taken out of the heating unit HP₂ to one of thecooling units CP₂, and takes out a wafer W already treated in thiscooling unit CP₂. The heating unit HP₂ and cooling unit CP₂ carry outpredetermined treatments for the newly loaded wafers W, respectively(steps S19 and S20).

Subsequently, the main transport mechanism T₂ accesses the receiverPASS₂ again, and repeats the above operation. This operation iscontrolled by the third controller 95. As a result, the wafers W areforwarded to the receiver PASS_(5B) in the order in which they areplaced on the receiver PASS_(2A). Similarly, the wafers W are forwardedto the receiver PASS_(2B) in the order in which they are placed on thereceiver PASS_(5B).

Next, operations taking place when the main transport mechanism T₁ couldnot place a wafer W on the receiver PASS₂ in the above step S9, andplaced the wafer W on the buffer BF2 instead, will be described. In thiscase, the third controller 95 controls the main transport mechanism T₂to place the wafer W it is holding on the receiver PASS_(2B) (Step S21).Then, omitting the substrate transport corresponding to step S9 of themain transport mechanism T₂, the third controller 95 lowers the maintransport mechanism T₂ to the position opposed to the buffer BF2, andcauses the main transport mechanism T₂ to hold the wafer W placed on thebuffer BF2. When the wafer W has been received from the buffer BF2, themain transport mechanism T₂ resumes substrate transport in the abovesteps S10 et seq. That is, the main transport mechanism T₂ transportsthe received wafer W to the edge exposing unit EEW₂ (step S10).

Thus, the main transport mechanism T₂ can directly receive the wafer Wwhich the main transport mechanism T₁ has placed on the buffer BF2. Thewafer W can be transferred efficiently, compared with the case where themain transport mechanism T₁ places the wafer W first placed on thebuffer BF2 on the receiver PASS₂ again, and the main transport mechanismT₂ receives the wafer W from the receiver PASS₂. Therefore, even whenthe main transport mechanism T₁ cannot place a wafer W on the receiverPASS₂, the wafer W can be transferred efficiently.

Next, operations taking place when the main transport mechanism T₂cannot place the wafer W on the receiver PASS₂ in the above step S21will be described. The third controller 95 controls the main transportmechanism T₂ to omit the substrate transport corresponding to step S21of the main transport mechanism T₂ and place the wafer W on the bufferBF2. Subsequently, the main transport mechanism T₂ is made to carry outthe substrate transport in the above steps S9 et seq.

It is preferable in this case that the main transport mechanism T₁ skipsthe above step S21 (to receive the wafer W from the receiver PASS_(2B)),accesses the buffer BF2, and receives the wafer W from the buffer BF2.

Thus, even when the main transport mechanism T₂ cannot place a wafer Won the receiver PASS₂. the main transport mechanism T₂, by placing thewafer W on the buffer BF2, can promptly shift to operation fortransporting other wafers W. On the story K2 of the developing block Bb,therefore, a series of treatments can be carried out for a plurality ofwafer W on time (as scheduled). There is no possibility of lowering thequality of development carried out for the wafers W.

[IF Transport Mechanisms T_(IF)—IF First Transport Mechanism T_(IFA)]

IF first transport mechanism T_(IFA) accesses the receiver PASS₅, andreceives the wafer W present on the receiver PASS_(5A) (step S11 a). IFfirst transport mechanism T_(IFA), holding the wafer W received, movesto the receiver PASS-CP, and loads the wafer W on the receiver PASS-CP(step S12).

Next, IF first transport mechanism T_(IFA) receives a wafer W from thereceiver PASS₇ (step S14), and moves to a position opposed to one of theheating and cooling units PHP₂. IF first transport mechanism T_(IFA)takes a wafer W having received post-exposure baking treatment (PEB)treatment from the heating and cooling unit PHP₂, and loads the wafer Wreceived from the receiver PASS₇ into the heating and cooling unit PHP₂.The heating and cooling unit PHP₂ carries out heat treatment for thenewly loaded wafer W (step S15 a).

IF first transport mechanism T_(IFA) transports the wafer W taken out ofthe heating and cooling unit PHP₂ to the receiver PASS_(5B).Subsequently, IF first transport mechanism T_(IFA) transports a wafer Wfrom the receiver PASS_(6A) to the receiver PASS-CP (Step S11 b, S12).Next, IF first transport mechanism T_(IFA) transports a wafer W from thereceiver PASS₇ to one of the heating and cooling units PHP₄. At thistime, IF first transport mechanism T_(IFA) takes out a wafer W havingreceived the post-exposure baking treatment (PEB) treatment in theheating and cooling unit PHP₄, and places the wafer W on the receiverPASS_(6B) (steps S14, S15 b, S16 b).

Subsequently, IF first transport mechanism T_(IFA) accesses the receiverPASS₅ again and repeats the above operation. This operation iscontrolled by the sixth controller 98.

Next, operations taking place when IF first transport mechanism T_(IFA)cannot place the wafer W in receiver PASS_(5B) in the above step S16will be described. The sixth controller 98 controls IF first transportmechanism T_(IFA) to omits the substrate transport by IF first transportmechanism T_(IFA) corresponding to step S16, and place the wafer W onthe return buffer BF_(IFB). Subsequently, the sixth controller 98 causesIF first transport mechanism T_(IFA) to carry out the transport in theabove steps S11 b and S12 et seq.

Thus, even when IF first transport mechanism T_(IFA) cannot place awafer W on the receiver PASS_(5B), IF first transport mechanism T_(IFA),by placing the wafer W on the return buffer BF_(IFB), can successivelyunload wafers W having undergone post-exposure baking (PEB) treatmentfrom the heating and cooling units PHP₂ on time. Therefore, even when awafer W cannot be placed on the receiver PASS_(5B), the post-exposurebaking (PEB) treatment can be carried out for wafers W effectively.

[IF Transport Mechanisms T_(IF)—IF Second Transport Mechanism T_(IFB)]

IF second transport mechanism T_(IFB) takes a wafer W out of thereceiver PASS-CP, and transports it to the exposing machine EXP. Then,IF second transport mechanism T_(IFB) receives an exposed wafer W fromthe exposing machine EXP, and transports it to the receiver PASS₂ (stepS13).

Subsequently, IF second transport mechanism T_(IFB) accesses thereceiver PASS-CP again and repeats the above operation.

In the substrate treating apparatus according to this embodiment, asdescribed above, the receivers PASS₂ and PASS₄ have the buffers BF2 andBF4 corresponding thereto, respectively. Even when the main transportmechanism T₁ or T₃ cannot place a wafer W on the receiver PASS₂ orPASS₄, the main transport mechanism T₁ or T₃ can place that wafer W onthe buffer BF2 or BF4. Thus, the main transport mechanism T₁ or T₃ cancontinue transporting wafers W. Even if other wafers W are being treatedin the film forming section (coating units 31 and heat-treating units41) when the main transport mechanism T₁ or T₃ becomes incapable ofplacing a wafer W on the receiver PASS₂ or PASS₄, a series of treatmentsincluding coating treatment and heat treatment can be continued forthose other wafers W on time. Thus, there is no possibility of loweringthe quality of treatment to form film (resist film and anti-reflectionfilm) on the wafers W.

Since the buffers BF2 and BF4 are arranged adjacent the receivers PASS₂and PASS₄, respectively, an amount of movement required for the maintransport mechanism T₁ or T₃ to access the buffer BF2 or BF4 does notdiffer greatly from an amount of movement required to access thereceiver PASS₂ or PASS₄. Therefore, a time taken when accessing thebuffer BF2 or BF4 can be made substantially the same as the time takento access the receiver PASS₂ or PASS₄. This allows the main transportmechanism T₁ or T₃ to carry out a subsequent transporting operationaccording to normal schedule.

The buffers BF2 and BF4 are open also in the direction accessed by themain transport mechanisms T₂ and T₄, respectively. Thus, the maintransport mechanism T₂ or T₄ can receive a wafer W temporarily placed onthe buffer BF2 or BF4. Even when the main transport mechanism T₁ or T₃places a wafer W on the buffer BF2 or BF4, the wafer W can betransferred efficiently from the main transport mechanism T₁ or T₃ tothe main transport mechanism T₂ or T₄.

Even when the main transport mechanism T₂ or T₄ of the treating block Bbcannot place a wafer W on the receiver PASS₂ or PASS₄, the maintransport mechanism T₁ or T₃ also can place that wafer W on the bufferBF2 or BF4. Thus, wafers W can receive high-quality developing treatmentin the treating block Bb.

Each buffer BF2 or BF4 can accommodate a larger number of wafers W thanthe number of coating units 31. Thus, even if wafers W are being treatedin all the coating units 31 when it becomes impossible for the maintransport mechanism T₂ or T₄ to place a wafer W on the receiver PASS₂ orPASS₄, all these wafers W under treatment can receive the series oftreatment following the coating treatment according to a predeterminedschedule. This prevents lowering in the quality of treatment for formingfilm on these wafers W.

Since each of the receivers PASS₁-PASS₆ has a sensor Sp for detectingpresence or absence of a wafer W, the control section 90 (specifically,the controllers 93-99) can determine properly whether a wafer W can beplaced on each of the receivers PASS₁-PASS₆.

The treating section 3 is divided into the two, upper and lower,stories, and wafers W can receive a series of treatments in parallel onthe respective stories. Thus, the apparatus has an increased throughput.The treating section 3 has a layered structure with the stories arrangedone over the other. The stories are arranged vertically as are the maintransport mechanism T₁ and main transport mechanism T₃, for example.This arrangement can avoid an enlarged installation area of thisapparatus.

This invention is not limited to the foregoing embodiment, but may bemodified as follows:

(1) In the foregoing embodiment, the buffer BF2 is stacked under thereceiver PASS₂, but the invention is not limited to this. For example,the buffer BF2 may be disposed over the receiver PASS₂, or may bejuxtaposed with the receiver PASS₂. Even with such a modification, themain transport mechanism T₁ can easily access the buffer BF2. A similarmodification may be made to the buffer BF4.

(2) In the foregoing embodiment, the buffer BF2 is open at opposite endsfacing the main transport mechanism T₁ and main transport mechanism T₂to be accessible also to the main transport mechanism T₂. The inventionis not limited to this construction. For example, the buffer BF2 may beopen only at the end facing the main transport mechanism T₁ to beaccessible only to the main transport mechanism T₁. A similarmodification may be made to the buffer BF4.

(3) In the foregoing embodiment, each of the buffers BF2 and BF4 hasbeen described as capable of accommodating five wafers W. This is notlimitative. Instead, for example, the buffer BF2 may be modified toaccommodate at least the number of wafers W that can be treatedsimultaneously in the film forming section on the story K1. Similarly,the buffer BF4 may be modified to accommodate at least the number ofwafers W that can be treated simultaneously in the film forming sectionon the story K3. This construction allows all the wafers W that can betreated simultaneously in the film forming section to be temporarilyplaced on the buffers BF2 and BF4. Therefore, whenever timing causeswafers W to be incapable of being placed on the receiver PASS₂ orreceiver PASS₄, these wafers W can be placed on the buffer BF2 or BF4after continuing a series of treatments including coating treatment andheat treatment on time for all the wafers W treated in the film formingsection.

Alternatively, the buffer BF2 may be modified to accommodate the numberof wafers W at least corresponding to the sum of the number of coatingunits 31 on the story K1 and the number of developing units DEV on thestory K2. Similarly, the buffer BF2 may be modified by taking intoaccount the number of developing units DEV on the story K4. With thisconstruction, even when it becomes impossible for the main transportmechanism T₂ or T₄ of the treating block Bb to place wafers W on thereceiver PASS₂ or receiver PASS₄, the wafers W treated in the developingunits DEV then can be developed with high quality.

(4) In the foregoing embodiment, the control section 90 determinespresence or absence of a wafer W on each of the receivers PASS₁-PASS₆based on a result of detection by a sensor Sp. The invention is notlimited to this. Instead, for example, it may be determined fromcontrols of the main transport mechanisms T₁ and T₂ carried out by thesecond and third controllers 94 and 95, whether the main transportmechanism T₂ has received a wafer W from the receiver PASS₂ after themain transport mechanism T₁ placed the wafer W on the receiver PASS₂. Ifthe wafer W has been received, it may be determined that the receiverPASS₂ has no wafer W (i.e. is vacant).

(5) Although each of the buffers BF2, BF4 and BFIF similarly has asensor for detecting presence or absence of a wafer W, the sensor may beomitted as appropriate as long as whether each buffer BF is loaded witha wafer W can be determined.

(6) In the foregoing embodiment, the treating block Ba includes theanti-reflection film coating units BARC. The invention is not limited tothis. A treating block including anti-reflection film coating units maybe provided separately from the treating block Ba. Or theanti-reflection film coating units BARC may be omitted.

(7) In the foregoing embodiment, the treating section 3 has a layeredstructure with two, upper and lower, stories. The invention is notlimited to this. The treating section 3 may be divided into three ormore stories. Or it is not necessary for the treating section 3 to havea layered structure (i.e. the treating section 3 may consist of onestory).

The modifications in paragraphs (6) and (7) above will be described withreference to FIG. 13. FIG. 13 a plan view showing an outline of amodified substrate treating apparatus. Like reference numerals are usedto identify like parts which are the same as in the foregoing embodimentand will not be described again.

As shown, the treating section 3 may be modified to include threetreating blocks B arranged horizontally. Specifically, ananti-reflection film coating block Bc, a resist film coating block Bdand a developing block Be are arranged in order from the ID section 1,with the developing block Be disposed adjacent the IF section 5.

The anti-reflection film coating block Bc has an anti-reflection filmcoating unit BARC, heat-treating units 41, and a main transportmechanism T₉ for transporting wafers W to and from the anti-reflectionfilm coating unit BARC and heat-treating units 41.

The resist film coating block Bd has a resist film coating unit RESIST,heat-treating units 41 and a main transport mechanism T₁ fortransporting wafers W to and from the resist film coating unit RESISTand heat-treating units 41.

The developing block Be has a developing unit DEV, heat-treating units42, an edge exposing unit EEW and a main transport mechanism T₂.

A receiver PASS₉ is provided between the anti-reflection film coatingblock Bc and resist film coating block Bd. The receiver PASS₉ is used totransfer wafers W between the main transport mechanism T₃ and maintransport mechanism T₁. A buffer BF9 is provided adjacent the receiverPASS₉. When the main transport mechanism T₃ cannot place a wafer W onthe receiver PASS₉, the wafer W is temporarily placed on the buffer BF9.The main transport mechanism T₃ corresponds to the third main transportmechanism in this invention. The receiver PASS₉ corresponds to the thirdreceiver in this invention. The buffer BF9 corresponds to the thirdbuffer in this invention.

Each of the above treating blocks Bc-Be is not divided into a pluralityof stories. Therefore, the treating section 3 does not have a layerstructure with a plurality of stories (it has a single-story structure).

In such modified embodiment, since the receiver PASS₉ has the buffer BF9corresponding thereto, even when the main transport mechanism T₃ cannotplace a wafer W on the receiver PASS₉, the main transport mechanism T9can place the wafer W on the buffer BF9. Thus, the main transportmechanism T9 can continue transporting wafers W. The anti-reflectionfilm coating block Bc can effectively carry out treatment for forminganti-reflection film on the wafers W.

(8) In the foregoing embodiment, the films formed on the wafers W in thetreating block Ba are resist film and anti-reflection film. Theinvention is not limited to this. A modification may be made to formother types of film on the wafers W.

(9) In the foregoing embodiment, each of the receivers PASS₁-PASS₆ has aplurality of (two) receivers, and one of the receivers PASS is selectedaccording to a direction for transferring wafers W. The invention is notlimited to this. Each of the receivers PASS₁-PASS₆ may consist of asingle receiver. In this case, wafers W transferred in whicheverdirection may be placed on the single receiver PASS.

This invention may be embodied in other specific forms without departingfrom the spirit or essential attributes thereof and, accordingly,reference should be made to the appended claims, rather than to theforegoing specification, as indicating the scope of the invention.

What is claimed is:
 1. A substrate treating apparatus for treating a plurality of substrates comprising: an indexer section; a treating section; one or more receivers; and one or more buffers; wherein the treating section has a plurality of stories arranged vertically, each story including: one or more coating units providing a coating treatment to the plurality of substrates with one or more treating solutions; one or more heat-treating units providing a heat treatment to the plurality of substrates; and a first main transport mechanism for transporting the plurality of substrates to and from the one or more coating units and the one or more heat-treating units; wherein the one or more coating units, the one or more heat-treating units and the first main transport mechanism being in the same arrangement on each respective story in the plurality of stories in plain view; wherein the one or more receivers are installed on each respective story; wherein the one or more buffers are installed on each respective story; wherein the indexer section is arranged to transport the plurality of substrates alternately to each respective story; and wherein on each story: the first main transport mechanism is arranged to transport the plurality of substrates received from the indexer section to the one or more coating units and the one or more heat-treating units, and place on the one or more receivers the plurality of substrates having a film formed thereon, and during a period of an abnormality when the first main transport mechanism cannot place the plurality of substrates on the one or more receivers, the first main transport mechanism temporarily places on the one or more buffers the plurality of substrates having the film formed thereon while a series of treatments including the coating treatment in the one or more coating units and the heat treatment in the one or more heat-treating units is continued according to a predetermined schedule for the plurality of substrates being treated at a time when the abnormality arose.
 2. The substrate treating apparatus according to claim 1, wherein the one or more coating units are arranged on one side of a transporting space in which the first main transport mechanism is installed; and the one or more heat-treating units are arranged on the other side of the transporting space.
 3. The substrate treating apparatus according to claim 1, wherein an arrangement of the one or more coating units and the one or more heat-treating units as seen from the first main transport mechanism identical on the respective stories.
 4. The substrate treating apparatus according to claim 1, wherein the first main transport mechanism is arranged to place the plurality of substrates on the one or more receivers in order to transfer the plurality of substrates to a different main transport mechanism.
 5. The substrate treating apparatus according to claim 1, wherein, at the time of the abnormality, the first main transport mechanism cannot place the plurality of substrates on the one or more receivers by a command prohibiting delivery to the one or more receivers.
 6. The substrate treating apparatus according to claim 1, wherein, during a normal operation, the plurality of substrates are placed only on the one or more receivers, and the plurality of substrates are not placed on the one or more buffers.
 7. The substrate treating apparatus according to claim 1, wherein the series of treatments carried out during the period of the abnormality is the same as a series of treatments carried out during a normal operation.
 8. The substrate treating apparatus according to claim 1, wherein the series of treatments carried out during the period of the abnormality includes the coating treatment, the heating treatment and a cooling treatment carried out in the stated order.
 9. The substrate treating apparatus according to claim 1, wherein during a normal operation, the plurality of substrates receive identical treatments on the respective stories.
 10. The substrate treating apparatus according to claim 1, comprising a controller for controlling the first main transport mechanism to place the plurality of substrates on the one or more receivers during a normal operation, and to place the plurality of substrates temporarily on the one or more buffers during the period of the abnormality.
 11. A substrate treating apparatus comprising: an indexer section; a resist film coating block; one or more receivers; and one or more buffers; wherein the resist film coating block has a plurality of stories arranged vertically, each story including: one or more coating units providing a coating treatment for a plurality of substrates with one or more treating solutions; one or more heat-treating units providing a heat treatment for the plurality of substrates; and a first main transport mechanism for transporting the plurality of substrates to and from the one or more coating units and the one or more heat-treating units; wherein the one or more coating units, the one or more heat-treating units and the first main transport mechanism being in the same arrangement on each respective story in plain view; wherein the one or more receivers are installed on each respective story; wherein the one or more buffers are installed on each respective story; wherein the indexer section is arranged to transport the plurality of substrates alternately to each story; and wherein on each story, the first main transport mechanism is arranged to transport the plurality of substrates received from the indexer section to the one or more coating units and the one or more heat-treating units, and place on the one or more receivers the plurality of substrates having film formed thereon; and during an abnormal operation when the first main transport mechanism cannot place the plurality of substrates on the one or more receivers, the first main transport mechanism temporarily places on the one or more buffers the plurality of substrates having film formed thereon while a series of treatments including the coating treatment in the one or more coating units and the heat treatment in the one or more heat-treating units is continued according to a predetermined schedule for the plurality substrates being treated when the abnormal operation occurred.
 12. The substrate treating apparatus according to claim 11, wherein the one or more coating units are arranged on one side of a transporting space in which the first main transport mechanism is installed; and the one or more heat-treating units are arranged on the other side of the transporting space.
 13. The substrate treating apparatus according to claim 11, wherein an arrangement of the one or more coating units and the one or more heat-treating units as seen from the first main transport mechanism is identical on each respective story.
 14. The substrate treating apparatus according to claim 11, wherein the first main transport mechanism is arranged to place the plurality of substrates on the one or more receivers in order to transfer the plurality of substrates to a different main transport mechanism.
 15. The substrate treating apparatus according to claim 11, wherein during the abnormal operation, the first main transport mechanism cannot place the plurality of substrates on the one or more receivers by a command prohibiting delivery to the one or more receivers.
 16. The substrate treating apparatus according to claim 11, wherein during a normal operation, the plurality of substrates are placed only on the one or more receivers, and the plurality of substrates are not placed on the one or more buffers.
 17. The substrate treating apparatus according to claim 11, wherein the series of treatments carried out during the abnormal operation is the same as a series of treatments carried out during a normal operation.
 18. The substrate treating apparatus according to claim 11, wherein the series of treatments carried out during the abnormal operation includes the coating treatment first, followed by the heating treatment and lastly a cooling treatment.
 19. The substrate treating apparatus according to claim 11, wherein a normal operation, the plurality of substrates receive the same treatments on each respective story.
 20. The substrate treating apparatus according to claim 11, comprising a controller for controlling the first main transport mechanism to place the plurality of substrates on the one or more receivers during a normal operation, and to place the plurality of substrates temporarily on the one or more buffers during the abnormal operation. 